At the end of the 1950ies high fidelity was complemented by the new thing: stereo.
In the beginning the phono industry was keen to promote the new idea and produced any sound as long as it was stereo. Therefore a lot of music and sounds went on the discs that today sound almost experimental, at least not quite as tamed as popular taste supposedly rigidly demanded, just a few years later.

Until the late 60ies, many records were still produced in stereo as well as in mono, while many mono records were remastered, sometimes losing sounds due to half-baked technology. Eventually the full color high fidelity mono had to give way to Living stereo, New orthophonic recording, Extra Stereo, Spinorama, Phase 4, Stereorama, Stereo action - The sound your eyes can follow!, Multiphonie-Stereo or Stereo spectrum.